Apparatus for heat treating tows of filamentary material



April 1957 J. M. SWALM, JR.. EFAL APPARATUS FOR HEAT TREATING TOWS 0FFILAMENTARY MATERIAL 4 Sheets-Sheet 1 Filed NOV. 18, 1953 INVENTORS JOHNM. SWALM JR ATTORNEY FRANClS J. SHEETS M Z MW April 16, 1957 J. M.SWALM, JR.. ETAL' 2,788,542

APPARATUS FOR HEAT TREATING TOWS 0F FILAMENTARY MATERIAL Filed Nov. 18,1953 4 Sheets-Sheet 2 INVENTORS FRANCIS J. SHEE TS BY cl g S: HMWL,ATTORNEY JOHN M. SWALM,JR.

April.l6, 1957 J. M. SWALM, JRi. ETAL 2,788,542

, APPARATUS FOR HEAT TREATING TOWS 0F FILAMENTARY MATERIAL Filed Nov.18, 1953 4 Sheets-Sheet 3 it 9. INVENTORS JOHN M. SWALM,JR. FRANCIS J.SHEETS ATTORN EY A ril 16, 1957 J. ,M. SWALM, JR.. EI'AL 2,733,542

APPARATUS FOR HEAT TREATING TOWS OF FILAMENTARY MATERIAL Filed NOV. 18,1953 4 Sheets-$heet 4 INVENTORS JOHN M. SWAUVLJR. FRANCS J. SHEETS BY MZ M ATTORNEY United States Patent 2,788,542 APPARATUS FOR HEAT TREATINGTOWS F FILAMENTARY MATERIAL John M. Swalm, Jr., and Francis J. Sheets,Charleston,

W. Va., assignors to Union Carbide and Carbon Corporation, a corporationof New York Application November 18, 1953, Serial No. 392,820

6 Claims. (Cl. 18-8) This invention relates to novel apparatus for thecontinuous treatment of filamentary materials. More especially itconcerns a novel apparatus for continuously annealing, stretching,drying, or otherwise treating a running yarn, filament or continuous towof a filamentary material with a circulating stream of a hightemperature isin operation at high temperatures. The followingdescription is directed principally to the form of the invention adaptedfor the continuous annealing of running tows made from synthetic resins.

Processes already are known for improving the physical properties offilaments and yarns made from synthetic resinous materials by subjectingsuch articles to various conditioning treatments, some of which involveheating the filaments and yarns and concurrently relaxing the same. Suchprocesses were not practicably applicable for the treatment of largebundles or tows of these filamentary materials moving through anenclosed treating zone because it was necessary to partially cool thechamber to lace the moving tow on the canted rolls manually. This,coupled with the time necessary to reestablish the operating conditions,temperature and roll speeds, resulted in the production of considerableunusable material.

Moreover, heretofore the temperatures of the apparatus parts within theheat-treating zone could not be maintained uniform during the timerequired to thread the heavy tow around the various hot rolls within theenclosed zone at the early stages of the operation, and subsequentthereto when for any reason the threads of the tow were broken orotherwise injured and the tow had to be again rethreaded around therolls within the hot chamber.

Among the more important objects of this invention are the following: anovel apparatus for heat-treating a moving filament, yarn or tow offilamentary material moving continuously under. a uniform tensionthrough an enclosed heat-treating chamber while maintaining such;

material at a uniform preselected elevated temperature, and whileregulating the amount of relaxation and annealing or of stretching ofthe filamentary material; and the provision of novel means for threadingor lacing a moving tow or yarn of a filamentary material around andbetween two or more canted driven rolls within an enclosed heat-treatingchamber while preventing substantial cooling of the chamber and enclosedoperating parts or objectionable change in the selected operatingconditions within the chamber.

Another object is the provision of apparatus having means forconcurrently moving two or more moving continuous tows or masses offilamentary material around sets of canted, tapered driven rolls Withinthe same enclosed heat-treating chamber in which a highly heated vaporof.fluid is circulating and having means controlled "ice from outside ofthe chamber for rethreading or lacing the tow around and between thecanted rolls during rotation of the latter while avoiding substantialtemperature drop in the chamber or interruption of the fiow of heatedvapors therethrough.

These and other objects will be evident from the following descriptionand the accompanying drawing.

In the accompanying drawing, wherein a preferred embodiment of theinvention is shown,

Fig. l is a side elevation of a heat-treating chamber and associatedparts;

Fig. 2 is a section taken along the line 2-2 of Fig. 1, looking in thedirection of the arrows, parts being omitted;

Figs. 3 to 6, inclusive, designate diagrammatically successive stages inthe threading of a tow through the apparatus;

Figs. 7 and 8, respectively, are aside view and a bottom view of the towlacing guide member;

Figs. 9 and 10, respectively, show diagrammatically in plan and inelevation a modification of annealing oven having a mechanically driventow-lacing device, parts being omitted; i t

Fig. 11 is an end view of a tapered roll having taperregulating means;and

Fig. 12 is a view taken along the line 12-12 of Fig. 11, looking in thedirection of the arrows, parts being broken away.

Referring now to Figures 1 and 2 of the drawing, the heat-treating andannealing apparatus comprises a fluid tight housing 11 formed of sheetmetal members and suitably mounted upon a supporting base 13. Thehousing members are covered on both sides with heat-insulating material15, preferably in the form of transite board or the like.

A plurality of horizontally disposed partitions 17 of heat-insulatingmaterial are mounted within the housing 11 and divide the same into aplurality of similar superposed elongated treating chambers, A, B, C, D,each having a tow inlet duct 18 and a tow outlet duct 20 for a tow T.

For circulating hot air, steam, or other hot gas or vapor through eachchamber A, B, C, D there is provided a circulating blower fan 19 drivenby a motor 21 through driving belt 23. The fan 19 discharges air intocontact with a suitable heating element 25, which may be an indirectheat exchanger, an electric heating element, or the equivalent, mountedin an enlarged area 26 of a conduit 27, which conducts the heated fluidthrough inlet headers 29 and vertically disposed inlet ducts 30 intoeach chamber A, B, C, D, adjacent the tow inlet end of such chamber. Theinlet end of fan 19 is connected with the tow outlet end of each chamberby a conduit 31 having branch linesv connected respectively with anoutlet duct 32 opening into each chamber adjacent the tow outlet end ofsuch chamber.

Extending within each chamber transversely thereof adjacent therespective tow inlet and outlet end walls and supported upon shafts 33,35, mounted for rotation on horizontal axes on bearings 37, 39, carriedby brackets 40, 40 supported on the frame are two laterally spacedtapered or cylindrical rolls 4]., 43, each having a flanged end and afree end, the latter end being spaced from the chamber wall oppositethat housing the flanged end.

The bearings 37, 39 are adjustable laterally by means of adjustingscrews and associated parts, and can be locked in selected position onthe brackets by lock nuts associated with the adjusting screws. Thus,the rolls can be canted to move their free ends toward and away fromeach other as desired, and to hold them in selected canted position.

For driving each pair of rolls in the respective chambers A, B,- C, D ata uniform selected rate there is provided a variable speed motor 47having its shaft 49 connected through shafts in interconnectedtransmission gear boxes G to corresponding driven shafts 51. Each of thelatter are operatively connected with the shaft'of a roll 41 ofarespective heat-treatingchamberthrough a shaft 53, transmission gears54, shaft 55, transmission gears 56 and flexible coupling 57. A clutchassembly 59- is mounted on shafts 51, 53.

- Each driven shaft 51 also is operatively connected with the shaft of aroll 43 of a corresponding heat treating 1 chamber through driven shaft51, gear box 54 and flexible coupling 60. p

' Forrotating'the respective rolls 41, 43, of each chamber A, B, C, andD independently of the rollsin the other chambers there isprovided aconduit 63 connected'with at source of compressed air and having itsdischarge end connectedthroughconduit 65'with the piston of an.airoperated valve 67 which isoperatively connected with clutch 59through linkage members 68, 69. A valve 70 in each air conduit.65.adjacent the tow dischargeend of a corresponding chambercontrols-operation of the clutch 59. The arrangement of parts is suchthat, upon opening any valve 70 the corresponding clutch 59 is actuatedand the'rolls 41, 43 in. the. chamber associated therewith are rotatedat a uniform selected rate.

For threading or lacing a. continuous tow or a yarn of filamentarymaterial through each and any heat-treating chamber andaround each ofthe rolls 41, 43, and in contact therewith during the heat-treatingoperation, there are provided two spools 72, 73, rotatably mounted uponbrackets 74, 75, located respectively at the tow inlet end of thechamber adjacent the side housing the shaft of roll 41, and at the towoutlet end of the chamber adjacent the free end of roll 43. The axis ofeach spool is provided with a crank 77 for rotating the spool. A wirecable 79'has its free ends wound around the spools 72, 73, for movementfrom one spool to the other, and extends into the chamber throughapertures in the walls thereof. Tow guides 80, 81 are secured,respectively, to the brackets 74, 75.

Mounted in each chamber for rotation upon bearings supported in the wallopposite that housing the roll shafts 33, 35, and in substantial axialalignment with the said rolls are respective sprocket wheels 82, 83,larger in diameter than the free ends of rolls 41, 43, the sprocketnearest the tow outlet port being provided with a hand crank 84.An'endless pintle chain 85 engages each of the sprockets '82, 83, andhas associated therewith a chain tension mechanism 86 of well-known typemounted on the chamber wall.

Secured to the chain 85 for movement therewith, and extending laterallythereof toward the rolls, isa tow lacing guide L of acorrosion-resistant metal such as stainless steel. This guide comprisesessentially two open spiral pigtailloops 89, 91 of. metal mounted uponorintegral with a supporting member 93 adapted .tonbe secured to a link.of chain v SS-by suitable means for free pivotal movement around itsown longitudinal axis. The tow guide issoconstructed and supported"that, during operation, the loop 89extends inwardly beyond the free endof rolls 41, 43, with the plane of the convolutionzapproximatelyperpendicular to the roll axes, whilethe other loop 91 is disposedbetween .the roll axes and the chain Withtheplane of the convolutionvertical andapproximately parallel to.

the rollaxes, the tow'guide swivelling on the chain for this purpose. Anelectric light 95 is mounted in each chamber to permit inspection of theinterior.

In the modification shown in Figures 9 and 10, a mechanical drive isshown for the chain 85 and tow lacing guide of each chamber A, B, C, D.The mechanism shown comprises a variable speed electric motor 101.havmgits shaft connected through transmission gears. 102, shaft 103, gears104 and shaft 105 with a sprocket 107 meshing with a pintle chain109having a chain tightcner 110 and idler sprockets 111 operativelyassociated therewith. The shafts of the sprockets-82, 83 in eachchamber, extend through the chamber wall; and the outer end of eachsprocket 83 is connected through a manually operated clutch 113 withashafthaving thereon a pintle sprocket 11S meshing with chain 109. Thearrangement of parts is such that, upon actuation of motor 101, thechain 109. and lacing device in each chamber is operated until theclutch 113 controlling such operation infany selected chamber, isdisconnected manually.

The adjustable-taper roll shown in Figures 11 and 12 comprises fivepartial frusto-conical segments 121 of corrosion-resistant metal, eachof which has its larger end pivotally mounted upon a link 123 secured tothe roll shaft 125. The small end of each segment 121 is pivotallyconnected with a link 127 which in turn is pivotally connected to an earof an externally threaded collar 129' keyed upon shaft 125. The collarcooperates with an internally threaded adjusting nut 131 having a setscrew 133 and snap ring 135 for locking'it in selected position on theshaft 125. By turning adjusting nut 131 the colhr 129 is moved along theshaft whereby linkage 127 raises one end of the roll surfaces and variesthe taper of the roll.

Each chamber A, B, C and D has at the tow inlet end and tow outlet endsglass doors to permit cleaning of the rollsand observing the operationconducted therein. Similarly, each of the chambers has an access dooradjacent the free end of roll 43 to permit threading of the advance endof the moving tow in the two pigtails of the tow guide.

In the operation of the apparatus, the fan 19 is actuated, and theheater 25 is turned on and a hot fluid, such as hot air or a mixture ofair and superheated steam, is circulated until the chambers A, B, C, Dhave reached the desired operating temperatures. Then the advancing endof a tow T is secured to a cable 79 and the handle 77 operated toconduct the tow to a point'near roll 43, with the tow guide L inposition adjacent thereto. Then door 139 is opened briefly and theforward end of the tow is threaded in. turn through the open loops inpigtails 81 and 91 of the tow guide and then is extended through the towoutlet port in the chamber wall to a suitable take up mechanism or theequivalent. Conveniently it is anchored yieldably by means of an air jetuntil the threading of the tow has been completed. Then door 139 isclosed and the roll-operating clutch 59 is actuated, whereupon the rolls41, 43 revolve in the same direction at the same uniform speed.

Concurrently the tow guide-carrying chain 85 is actuated by means ofcrank 84or by the motor 101 and associated parts (Figs. 9 and l0)wherebythe tow guide is traversed once around the chain path during which thetow being withdrawn uniformly under a selected low tension from thechamber by suitable means passes successively through loops 89 and 91 ofthe guide and thence to the tow outlet port 20 while the guide, and towmoving therethrough, is laced over and around roll 43 and then under,around, and over. roll 41. Figs. 3 to 6 show diagrammatically thepositions of the tow during four successive stages of a single traverseof the tow guide during an annealing operation with tow moving through aheat-treating chamber.

When the desired number of convolutions of tow have been laid inposition upon and between the rolls 41, 43, actuation of the link chain85 and tow guide L. is dis: continued, and the tow can readily be liftedmanually from the two open pigtail guides of the tow guide L while thetow is in motion. 7

The tow continues to move through the inlet port 18 of each chamber, andprogresses, due to the cant of rolls 41, 43, through a multiplicity ofclosely spaced paths, to the outlet port 20. By increasing the number ofsuch paths of tow in a chamber and the speed of rolls 41', 43,

M the contact time of the tow with the heated fluid can be varied widelyto meet any requirements. The time of contact is limited only by thepermissible close proximity of adjacent paths of the tow and the lengthsof the rolls.

The following further illustrates the invention. Using apparatus of thetype described and shown in Figs. 1 to 8, a 7500 filament, threedenier-per-filament tow, made from a copolymer of acrylonitrile andvinyl chloride and containing about 60% of vinyl chloride, was fed at arate of 430 feet per minute into a heating chamber maintained at 138 C.and was lapped twenty times around the canted rolls 41, 43, each ofwhich was tapered inwardly in the direction of their free ends asufficient amount to permit a 28% relaxation and shrinkage of the tow(in length) during a 55 seconds dwell of the tow within the chamber. Thethus annealed tow was coated with a lubricant and was ready for cuttingand crimping into staple fibers suitable for commercial use, and forcrimping such fibers.

Physical properties of individual filaments in a tow Prior to AlterAnnealing Annealing By regulating the degree of taper of the rolls 41,43, the extent of relaxation or shrinkage of the tow in length duringthe dwell thereof in the heating chamber is ,controlled.

By employing canted tapered rolls 41, 43, which are supported at theirends of smallest diameter, the tow can be heat-treated and concurrentlystretched a preselected amount during the dwell thereof in the chamber.

Cylindrical rolls can be substituted for the tapered rolls 41, 43 whenthe apparatus is used for drying tows or yarns and shrinkage of thematerial is small. The construction of the apparatus and its operationis otherwise the same.

By the use of the novel apparatus and tow-threading mechanism of thisinvention it is now possible to avoid or minimize the losses of townormally occurring when the moving tow must be threaded a plurality oftimes around hot annealing rolls. Heretofore, it has been necessary toat least partially cool the heat-treating chamber in order to permitmanual threading of the moving tow on the canted rolls. The resultantincompletely heat-treated tow ordinarily is unsatisfactory and isdiscarded or used for a less exacting purpose.

Furthermore, the loss of service time of the heat-treating apparatusduring which the chambers are open and are cooling to permit full manualthreading of the tow around the rolls have been minimized, for the towthreading can now be done with the chambers and rolls at full operatingtemperatures.

The invention is susceptible of modification within the scope of theappended claims.

We claim:

1. Apparatus for heat-treating a running tow of filamentary material,which comprises an elongated enclosed chamber having side walls and endwalls, and having a tow inlet port and a tow outlet port; means fordirecting a stream of hot air through said chamber; two laterallyspacedcanted rolls mounted for rotation within said chamber on approximatelyparallel axes; means for rotating the rolls in unison at the same rate;and means for threading the tow between each of said rolls, whichcomprises two rotatable members mounted in the chamber wall adjacent thefree ends of said rolls for rotation on axes respectively in at leastapproximately longitudinal alinement with the axis of rotation of acorresponding roll, said rotatable members being positioned between thefree ends of the rolls and the adjacent wall of the chamber, thediameterof each of said rotatable members being greater than that of the freeends of the rolls, an endless conveyor operatively connected with thetwo rotatable members, means for driving the rotatable members andconveyor at a selected rate, a tow lacing guide member carried by saidconveyor and having an open tow guide portion adapted to travel in aplane embracing the free ends of the rolls, and having a second open towguide portion adapted to travel in a path disposed between the free endsof the rolls and the adjacent Wall of the chamber; an access door in thechamber wall adjacent the roll nearest the tow outlet end, said doorhaving a closure; and means for conducting the forward end of anadvancing tow into the tow inlet port, through the chamber, and outthrough the tow outlet port.

2. Apparatus for heat-treating a running tow of filamentary material,which comprises at least one elongated substantially closed chamber,each having a restricted tow inlet port and a restricted tow outletport; two laterally spaced tow supporting rolls extending transverselyof said chamber, each supported at one end for rota tion on itslongitudinal axis, and having the free end spaced from the opposite wallof said chamber, said rolls being in canted relation to each other;means for rotating each of said rolls in unison at a uniform rate; meansfor circulating heated air in a closed path that includes said chamber,which comprises a fluid outlet conduit connected with said chamber atthe tow outlet end; a fluid inlet conduit connected with the chamberadjacent the tow inlet end; means for withdrawing vapors from said fluidoutlet conduit and for introducing the same into said fluid inletconduit; heater means: operatively connected with the last-named meansfor heating vapors flowing to said fluid inlet conduit; and mechanismfor threading a tow of filamentary material around said rolls while thechamber and rolls are at high operating temperatures and moving at highoperating speeds, which mechanism comprises two rotatable membersmounted in the chamber wall adjacent the free end of the rolls andhaving their axes of rotation, respectively, in line with the axis ofrotation of a corresponding roll, and an endless conveyor operativelyconnecting the two rotatable members, means for driving the rotatablemembers and conveyor at a selected rate, and tow lacing guide meanscarried by said conveyor having a tow guide portion adapted to travelalong a path lying in a plane intersecting the free ends of the rolls,and having a second tow guide portion adapted to travel in a pathdisposed between the free ends of the rolls and the adjacent wall of thechamber; a door mounted in the chamber wall adjacent the tow outlet endof the chamber; and means for conducting the forward end of an advancingtow into the tow inlet port, through the chamber, and out through thetow outlet port.

3. Apparatus as defined in claim 2, wherein the towsupporting rolls aretapered inwardly in the direction of their free ends.

4. Apparatus as defined in claim 2, wherein the towsupporting rolls havecylindrical lateral surfaces.

5. Apparatus as defined in claim 2, wherein the towsupporting rolls aretapered inwardly in the direction of their supported ends.

6. Apparatus as defined in claim 2, wherein the towsupporting rolls aretapered; together with means for regulating the degree of taper of therolls; and means for regulating the degree of cant of the rolls.

References Cited in the file of this patent UNITED STATES PATENTS2,055,820 Gram Sept. 29, 1936 2,155,324 Moritz Apr. 18, 1939 2,319,812Gram May 25, 1943 2,516,157 Stanley -July 25, 1950

1. APPARATUS FOR HEAT-TREATING A RUNNING TOW OF FILAMENTARY MATERIAL,WHICH COMPRISES AN ELONGATED ENCLOSED CHAMBER HAVING SIDE WALLS AND ENDWALLS, AND HAVING A TOW INLET PORT AND A TOW OUTLET PORT; MEANS FORDIRECTING A STREAM OF HOT AIR THROUGH SAID CHAMBER; TWO LATERIALLYSPACEDCANTED ROLLS MOUNTED FOR ROTATION WITHIN SAID CHAMBER ON APPROXIMATELYPARALLEL AXES; MEANS FOR ROTATING THE ROLLS IN UNISON AT THE SAME RATE;AND MEANS FOR THREADING THE TOW BETWEEN EACH OF SAID ROLLS, WHICHCOMPRISES TWO ROTATABLE MEMBERS MOUNTED IN THE CHAMBER WALL ADJACENT THEFREE ENDS OF SAID ROLLS FOR ROTATION ON AXES RESPECTIVELY IN AT LEASTAPPROXIMATELY LONGITUDINAL ALINEMENT WITH THE AXIS OF ROTATION OF ACORRESPONDING ROLL, SAID ROTATABLE MEMBERS BEING POSITIONED BETWEEN THEFREE ENDS OF THE ROLLS AND THE ADJACENT WALL OF THE CHAMBER, THEDIAMETER OF EACH OF SAID ROTATBLE MEMBERS BEING GREATER THAN THAT OF THEFREE ENDS OF THE ROLLS, AN ENDLESS CONVEYOR OPERATIVLELY CONNECTED WITHTHE TWO ROTATBLE MEMBERS, MEANS FOR DRIVING THE ROTATABLE MEMBERS ANDCONVEYOR AT A SELECTED RATE, A TOW LACING GUIDE MEMBER CARRIED BY SAIDCONVEYOR AND HAVING AN OPEN TOW GUIDE PORTION ADAPTED TO TRAVEL IN APLANE EMBRACING THE FREE ENDS OF THE ROLLS, AND HAVING A SECOND OPEN TOWGUIDE PORTION ADAPTED TO TRAVEL IN A PATH DISPOSED BETWEEN THE FREE ENDSOF THE ROLLS AND THE ADJACENT WALL OF THE CHAMBER; AN ACCESS DOOR IN THECHAMBER WALL ADJACENT THE ROLL NEAREST THE TOW OUTLET END, SAID DOORHAVING A CLOSURE; AND MEANS FOR CONDUCTING THE FORWARD END OF ANADVANCING TOW INTO THE TOW INLET PORT, THROUGH THE CHAMBER, AND OUTTHROUGH THE TOW OUTLET PORT.